Trimming mechanism for sewing machines



J. a. RINGE I TRIHMING MECHANISM FOR SEWING MACH INES 1 a, n NW N h E U h I 1 1 I I u l I I 1 I I I I I I x I \l WITNESSES:

1 526436 J. c. RINGE TRIMMING MECHANISM FOR SEWING MACHINES Filed Sept. 8, 1922 2 Sheets-sheaf. 2

wnmzssss; INVENTOR a; @264 I Joxr/v C/P/A/OZ. mp R1 ATTORNEY Patented Feb. 1?, i925.

JOHN C. RINGE, OF STRATFORD, CONNECTICUT, ASSIGNOR TO THE SINGER MANUFAC- TUBING COMPANY, 015' ELIZABETH, NEW JERSEY, A CORPORATION OF NEVV JERSEY.

TRIMMING MECHANISM FOR SEWING lvIACHINES.

Application filed September 8, 1822. Serial No. 586,900.

To all whom it may concern:

Be it known that I, JOHN C. Enter, a citizen of the United States, residing at Stratford, in the county of Fairiield and 5 Stateof Connecticut, have invented certain new and useful Improvements in Trimming Mechanisms for Sewing Machines, of which the following is a specification, reference being had therein to the accompanying draw ings.

This invention relates to trimming mechanisms for sewing machines and more par ticularly to improvements in commercially termed under-edge trimming mechanisms designed for trimming the free edge of the undermost of two or more plies of material in the operation of uniting said plies by stitching, whereby the trimmed edge of the lower ply is'more or less within the line of the upper ply edge as is common in the man ufacture of shoes.

Under-edge trimming mechanisms are well known in the art to which this invention appertains, being exemplified for instance by the disclosures in the United States patents to W. A. Neely, No. 628,227, dated July a, 1899, and to C. H. Foster, No. 630,209, dated Aug. 1, 1899. In one form of these earlier under-edge trimmers, the trimmer-blade carrier is supported below the overhanging arm of the sewing machine for reciprocatory movements in a direction inclined to the path of movement of the needle requiring a definite amount of clearance below said overhanging arm and in another form for oscillatory movement in an arcuate path. Both of these earlier mechanisms constitute objectionable obstructions below the overhanging arm of the machine, particularly when it is desired to embody other mechanisms therein. Furthermore, a large majority of underedge trimmers require the use of a spring pressed follower in the throat-plate subject to clogging by the. trimmed-oli' material.

The present invention has for its object to provide an improved under-edge trimming mechanism leaving an unobstructed space below the overhanging arm of the sewing machine and obviating the necessity oi employing a spring-pressed follower in the throat-plate.

To the attainment of the object of this invention, the present improvement in its preferred embodiment comprises a trimmer-bar mounted for reciprocatory-oscillatory movements in the head of the overhanging bracket-arm of a continuous-feed sewing machine such as disclosed in the United States patent to H. Corrall and B. A. Stevens, N'. 1,414,625, of May 2, 1922. Reciprocatory movements are imparted to the trimmer-bar from an eccentric on the rotary needle-actuating shaft through suit able connections shiftable to throw the trimmer-bar into and out of operation during the operation of the machine.

The trimming-knife is secured upon a bracket carried by the lower end of the trimmer-bar and is disposed in an inclined position relative to the throat-plate of the sewing machine. The trimming-knife is furthermore provided with the usual depending guide-finger projecting into an aperture in the throat-plate, while the shear ing edge of the knife coacts with a beveled edge of a ledger-blade adjacent which a depression is formed in the throat-plate to provide the necessary clearance. This construction obviates the requirement of a spring pressed follower to close up an aperture in the throat-plate.

In some forms of under-edge trimmers a spring-pressed follower is essential to maintain a shearing relation between the reciprocating and stationary blades. According to the present construction, the trimmingknife is bodily shifted laterally by positive- 1y acting means comprising an inclined cam opposed by an adjustable screw both disposed in the head of the overhanging arm and constituting a guideway for the trimmer-bar. In order to provide for lateral movement of the trimmer-bar to maintain shearing relation between the knife and ledger-blade, the upper end of the trimmerbar is constructed to coact with a guideway whereby a reciprocatory-oscillatory movement of the trimmer-bar is permitted under firm guidance.

When the trimmer-blade is disposed in operative position and the sewing machine is set in operation, the under edge of two or more plies of material is severed by an under-cutting stroke, so that the edge of the lower layer will be slightly within the edge of the upper layer and will therefore be concealed by the latter.

In the accompanying drawings, Fig. 1 is a front side elevation, partly in section, of a continuous feed sewing machine embodying the presentimprovedtrimming mechanism. Fig. 2 is a sectional view of Fig. 1 substantially on the line AB. Fig. v3 is a front end elevation of the head and clothplate of this sewing machine. Fi 4% is a longitudinal section of the presser-bar and showing theadjacent trimmer-bar. Fig. 5

is a longitudinal section of the overhang ing bracket-arm head adjacentthe trimmerbar. Fig. 6 isa sectional view of Fig. 3'

substantially on the line C-D. Figs. 7

and 8 are perspective views of the trimmerbar guide-brackets. Fig. 9 is a top plan view of the throat-plate and attached ledgerblade. 7 g

Referring to the drawings, the sewing machine shown isconstructed substantially in accordance with'the disclosure in the Corrall et al. Patent No.1, 1-14,625 hereinbefore referred to and is provided'with the bed-plate 1, the upper surface of which serves as the cloth-plate 2. Rising from the bed-plate is the hollow standard 3, curving laterally into the overhanging arm 4 terminating in the head 5. Suitably ournaled in the overhanging arm is the main or driving shaft 6 carrying at one end the belt-pulley 7 shaft-flange 8 provided with the crank-pin 9. Embracing the-crank-pin 9 is the apertured and laterally offset 'end of the link 10 of which the opposite end is suitably connerted'with the needle-bar 11 to impart end-wise reciprocations to the latter upon rotation of the driving shaft 6.

The needle-bar 11 carries the needle 12 and is journaled for endwise reciprocation in the swinging frame 13 pivotally sup ported at its upper end upon the fulcrumpin 14 secured in the head5 bymeans of the set-screw 15; In order to impart swinging movements to the frame 13 in the line of scam-formation, the lower end of the frame is suitably connected with the crank arm 16 upon one end of the rock-shaft 17, jonrnaled in bearings provided in the overhanging'arm. The rock-shaft 17 which is positioned below and extends substantially parallel to the driving shaft 6 has secured thereupon the forked arm 18 actuated by the eccentric 19, secured in a well known manner upon the driving shaft 6 to permit of adjustment of the throw of the arm 18. The needle-thread take-up employed may be of any suitable construction and is therefore not described herein. 7 v

Cooperating with the needle 12 in the formation of lock-stitches is the loop-taker and atits oppositeend the 20 secured upon the vertical shaft 21 and rotated twice during each complete reciprocation of the needle-bar. Accordingly the shaft 21 is suitably geared to one end of the horizontal loop-taker actuatingshaft 2a, journaled beneath the cloth-plate 2 and of which the other end is geared in like manner Wlihl the vertical, intermediate shaft 28, journaled in the standard?) and driven by the main-shaft 6 through gears having a two-to-one ratio.

-The intermediate shaft 23 also has worm and worm-wheel connections with the feedwheel actuating shaft 22, journaled beneath the cloth-plate'2 and geared with the feedwheel 25. By means of these connections, the feed-wheel 25 is continuously rotated during the operation of the machine. and therefore comprises continuously feeding work-feeding means. The feed-wheel 25 projects through a slot in the throat-plate 26 to engage the work and is opposed by the roller-presser 27, which may be of any well known construction and which is shown as carried by a swing-out bracket 28 secured upon the presser-bar 29. The presser-bar 29 is journaled for endwise vertical movements in bushings, as 30, secured in apertures provided in the head 5 and is illustrated as of tubular construction. Inserted within the tubular presser-bar is a coiled spring 31 interposed between the base of the tubular portion of the bar and a trimmerbar lifting rod 32. The presser-bar may be raised 'to lift the roller-presser 27 above the work, against the action of any suitable depressing spring, by means of any usual hand and foot lifter levers.

The upper end of the lifting rod 32 is rounded and bears against an angular plate 33 in the present instance secured upon the upper end of a trimmer-bar 34 by means of screws, as 35. This trimmer-bar 34 is journaled within the head 5 for endwise reciprocating and laterally vibrating movements resulting in a path of movement inclined with respect to the plane of the clothplate. In its preferred embodiment the upper end of the trimmer-bar 34 is slidingly fitted in a rectangular recess 86 provided in the head 5, a rounded protuberance 37 on the bar bearing against the base 38 of the recess under the constraining action of a rounded surface 39 provided on a plate 40, secured by screws as ll, upon the machine head and closing the recess. The upper guide for the trimmer-bar therefore comprises a sliding fulcrum-support. Adjacent its lower end, the trimmer-bar 8% is provided with substantially parallel inclined surfaces 42 and as comprising a guide for deflecting the bar laterally, in direction transverse to the line of seameformation, Coasting with the surface 42 is an inclined shoulder or guideway 44 provided upon an angular plate 45 linger 62.

secured by screws, as 46, upon the head 5. Opposed to the guideway 4A is an adjustable screw 47 hearing against the: surface a3 and threaded into an angular plate 48 secured by screws, as 49, upon the machine head. The screw d7 maybe maintained in adjusted position by means of a lock-nut 50. The trimmer-bar adjacent to the guideway la is slidingly guided by a flat surface 51 provided on the machine head 5 and on the side opposite thereto by the guidesurface 52 provided on the angular plate adjacent-to the shoulder 44:. The surface 53 of the angular plate 48, together with a flattened surface 5% on the machine head, afford a guieeway for a lug 55 projecting from the swinging needlebar carrying frame 13, maintaining the swinging movements of the frame in the line of feed.

Adjustably secured upon the lower end of the trimmer-bar, by means of screws as 56, is a blade-carrying bracket 57 having an inclined depending member 58. Secured by means of screws, as 59, upon the member 58 is a trimming-knife 6O inclined with respect to the cloth-plate and having the usual cutting edge 61 and guide-finger 62. The angle of inclination of the trimming blade or knife may be adjusted by means of a setscrew 63 in connee-tionwith the blade securing screws 59, which latter also serve to secure the finger-piece 64- upon the member The trimming-knife eoacts with a beveled or inclined edge 65 of a ledgerblade 66 secured by screws as 67 upon the recessed upper surface of the throat-plate 26. It is evident that instead of securing the ledger-blade upon the throat-plate, it might be formed integral therewith. Adjacent the edge 65, the throat-plate 26 is formed with a depression 68 to provide clearance for the cutting edge of the trimming-knife and also with an aperture 69 for the guide- It will be observed that the ledger-blade 66 is reversible by the provision of an inclined edge 65 thereupon on the side opposite the active edge 65. Consequently, when the edge 65 is worn after extended use, the ledgenblade may be reversed and the edge 65 brought into edective position for coaction with the movable trimming-knife.

In order to endwise reciprocate the trimmer-bar, it is provided with a notch 70 adapted to be entered by a stud 71 projecting from an arm 72 carried by one end of a rock-shaft 73. The rock-shaft 7 3 is journaled for oscillatory and endwise sliding movements in bearings provided in lugs as 74 on the rear side of the overhanging bracket-arm. Projecting from this rockshaft 73 is a forked arm 75 straddling an eccentric 76 secured upon the driving shaft 6. It is evident that upon rotation of the driving shaft 6, oscillatory movements will be imparted to the rock-shaft '73, which movements are transmitted to the trimmer bar when the stud 71 is in engagement with the notch 70. Means are, however, provided for disengaging the trimmer-bar from its actuating mechanism. For this purpose, the inner end of the rock-shaft 73 is provided with a peripheral groove 77 straddled by a forlr 78 on a shift-arm 7E). The shift-arm 79 is secured upon a transverse fulcrum-shaft 8O journalled in a bearing boss 81 on the top of the overhanging arm a and which shift-arm has a lateral projection 8:2 engaged by a coiled spring 83 seated on a lug projecting from the overhanging arm of the machine. The shiftarm 7 9 curves forwardly under the. bracketarm t for convenience in shifting it in a direction toward the head 5 against the action of the spring 83. Vi hen so shifted, the fork 7 8 acts upon the rock-shaft 73 to slide the latter endwise in its hearings in a direction to disengage the stud 71 frhm the notch 70, whereupon the trimmer-bar is free to respond to the action of the spring 31 trans mitted through the shifting rod 32 and is lifted to an inoperative position. This 1noperative position is determined by the head of a screw 85, threaded into the lower end of the trimmer-bar and engaging the machine frame. When the. rock-shaft 73 is shifted, the fork 75 slides on the eccentric 76, which latter is elongated for this purpose. lVhen it is desired to return the trimmer-bar to its operative position, it may be depressed against the action of the spring 31 by pressure upon the finger-piece 64 until the stud 71 snaps into engagement with the notch 70 by reason of the action of the spring 83.

The function of under-edge trimming mechanisms is so well understood in the art to which this improvement appertains that no further description herein is deemed essential to an understanding of the present invention. Suffice it to mention that it is the common practice to sever the edge of the work at an acute angle with respect to the work-surface, necessitating a definite angular relationship between the trimmingknife and the work. Furthermore, the trimming-knife must maintain a shearing relation with a coacting ledger-blade or its equivalent. In the present improvement, this relationship is maintained in a highly satisfactory manner by imparting oscillatory movements to the trimmer-bar in a direction transverse to the line of seamformation, obviating undesirable obstruction of space under the overhanging arm and also unreliable followers in the throatplate. A slight clearance is provided be tween the screw 47 and the inclined surface l3 at the time of cutting, thereby procuring an unopposed action of the guideway 44 to hold the knifein shearing relationship with its coacting ledgenblade.

Having thus set'torth the nature of the invention, what I claim herein is 2- 1. In asewing machine, in combination, a trimmer-bar, a trimmingdrnii e carried by said trimmer-bar having a cutting edge substantially parallel with the line of seam-tormation, actuating means for endwise reciprocating said trimmer-bar, and means for imparting sidewise movements to said trimmer-bar in a direction substantially transverse to the cutting edge of the trimmingknife.

2. In a sewing machine, in combination, a trimmer-bar, a trimming-knife carried by said trimmer-bar in inclined position with respect thereto,v actuating means for endwise reciprocating said trimmer-bar, and a guide acting to impart oscillatory movements to the trimmer-bar in a direction substantially transverse to the line of seam-formation.

In an under-edge trimming mechanism for sewing machines, in combination, a trimmer-bar, a trimming-knife carried by said trimmer-bar, actuating means for endwise reciprocating said trimmer-bar, and an inclined guide and coacting member for imparting sidewise movements to said trimmer-bar in a direction substantially transverse to the line of seamdi'ormation.

4c. In a sewing machine, in combination, a cloth-plate, a trimmer-bar, actuating means for endwise reciprocating said trimmer-bar, a trimming-knife rigidly carried by said trimmer-bar in position inclined with respect to said cloth-plate, a ledger-blade cooperating with said trimmingknite to sever the material, and means effective during the endwise reciprocating movements of said trimmer-bar for bodily shitting said trimming-knite laterally in a direction toward said ledger-blade to maintain shearing relation with the latter during the trimming operation.

5. In a sewing machine, in combination, a cloth-plate, a trimmer-bar, actuating means for endwise reciprocating said trimmer-bar, a trimming-knife rigidly carried by said trimmer-bar in position inclined with respect to said cloth-plate, an inclined ledger-blade surface cooperating with said. trimming-knife to sever the material, means effective during the endwise reciprocating movements of said trimmer-bar for bodily shifting said trimming-knife laterally in the direction of said inclined ledger-blade to maintain shearing relation with the latter during the trimming operation, and means operable during the operation of the machine for positioning said trimmer-blade in inoperative position.

6. In a sewing machine, the combination with a cloth-plate, and an, overhanging arm, of a trimmer-bar, a tr' inning-knife carried by said trimmer-bar, actuating means tor endwise reciprocating said trimmer-bar, and guiding means for the trinnner-bar provided within said overhanging arm acting to impart lateral movements to said trimmer-bar by endwise reciprocation thereof.

Z. In a sewing machine, the combination with a cloth-plate, and an overhanging arm, of a trimmer-bar, a trimming-knife carried by said trimmer-bar, actuating means for endwise reciprocating said trimmer-bar, guiding means for the trimmer-bar acting to impart lateral movements to said trimi'ner-bar by endwise reciprocation thereof, and adjustable means for maintaining said guiding means effective.

8. In a sewing machine, in combination, a trimmer-bar, a trimming-knife carried by said trimmer-bar, actuating means for endwise reciprocating said trimmer-bar, means for imparting sidewise movements to one end of said trimmer-bar in a direction substantially transverse to the line of scamt'ormation, and a pivot-guide for the other end of said trimmer-bar.

9. In a sewing machine, in combination,

a throat-plate, a trimmer-bar, a trimmingknife carried by said trimmer-bar in a position inclined with respect to said throatplate, actuating means for endwise reciprocating said trimmer-bar, an inclined guide for imparting sidewise movements to the trimming-knife carrying end of said trimmer-bar in a direction substantially transverse to the line of seam-formation, and a pivot-guide for the other end of said trimmer-bar.

10. In a sewing machine, in combination, a throat-plate, a trimmer-bar, a trimmingkni'fe carried by said trimmer-bar in a posi tion inclined with respect to said throatplate, actuating means for endwise reciproeating said trimmer-bar, an inclined guideway for imparting sidewise movements to the trimming-knife carrying end of said trimmer-bar in a direction substantially transverse to the line of seam-formation, adjustable means for maintaining saidtrimmer-bar in engagement with said inclined guideway, and a pivot-guide for the other end of said trimmer-bar.

name to this specification.

JOHN G. RINGE. 

